Turbine shaft cooling



I point in the Patented Feb. 19, 1946 Walter A. Ledwith, Hartford,

United Aircraft Corporation,

Conn, assignor to East Hartford,

Conn., a corporation of Delaware Application May 11; 1943,

11 Claims.

Thi invention relates to the cooling of a turbine shaft.

In the co-pending application of Kalitinsky and Buck, Serial No. 486,609filed May 11, 1943, the

turbine shaft through which coolant is circulated is provided with abaflle which prevents the flow of fluid beyond a predetermined shaft. Afeature of the present invention is the mounting of this battle withinthe shaft so that the baffle is wedged in place.

Another feature of this invention is the tapering of a part of therecess so that the baflle may be wedged in the recess by endwisepressure. Another feature is the use of a coolant tube extending fromthe open end of the recess to the baiile, and a spring urging the tubeendwise against the bafile to hold the tube and baflle in place.

Other objects and advantages will be apparent from the specification andclaims, and from the accompanying drawing. which illustrates what is nowconsidered to be a preferred embodiment of the invention.

The single figure is a sectional view through the cooling structure forthe turbine shaft.

The turbine shaft I is journaled in a bearing 1 2 and has a recess l4extending from the end of the shaft toward the power section It. Thispower section becomes heated during operation of the turbine (especiallyin gas turbines) and the shaft conducts heat from the power sectiontoward the bearing. The wall surfaces of recess I4 taper, at leastadjacent the inner end, so that the walls diverge in a direction towardthe outer end of the recess.

A cup-shaped baflle [8 extends across the recess adjacent the inner endand has an outer peripheral surface engaging the tapering walls of therecess and wedged in place by endwise pressure. A coolant tube 20extends from a cap 22 at the outer end of the recess to the baffle. Theinner end of the tube has a flange 24 engaging a shoulder 26 in thebafile. The outer end of the tube is supported radially by cap 22 and isfree to move endwise. A spring 28 surrounding the tube and positioned ina sleeve 30 integral with the cap engages a flange 32 on the tube. Thisspring urges the tube and the baffle endwise and wedges the bafflesecurely within the recess. Coolant is directed into the outer end ofthe tube through a nozzle 34. Coolant discharges from the tube onto thesurface of baflle l8 through radial opening 36 and escapes from recessI4 through one or more slots 38.

Nozzle 34 extends centrall through opening ts in cap 22 which may beslightly larger in diameter than the nozzle. As this opening is Smallerin Serial No. 486,621

.limited to the specific embodiment herein illustrated and described,but may be used in other ways without departure from its spirit asdefined by th following claims.

Iclaim:

1. A shaft having a' recess with a tapering wall, a battle having aperipheral surface fitting said wall, and resilient means for holdingsaid bafile in position.

2. A shaft having a recess with a tapering wall, a baffie having aperipheral surface fitting said wall, a tube engaging said bafile andresilient means acting on the tube to Wedge the baffle in the recess.

3. A shaft having a recess with a tapering wall, a baffle having aperipheral surface fitting said wall, a tube extending axially of saidrecess and engaging said baflie, a cap at the end of the recess and aspring between said cap and tube for urging said tube and baiileendwise.

4. A shaft having a recess with a tapering wall, a baffle having aperipheral surface fitting said wall, a tube engaging said baiile andresilient means acting on the tube to wedge the baffie in the recess,said tube being thickened between its ends to control its criticalspeed.

5. A shaft having a recess with a tapering wall, a bafiie having aperipheral surface fitting said wall, a tube engaging said baflle andresilient means acting on the tube to wedge the baffle in the recess,the wall thickness of aid tube varying between its ends for controllingits critical speed.

6. A shaft having a recess with a tapering wall, a baiile having aperipheral surface fitting said wall, a tube extending axially of saidrecess with the inner end engaging and supported by the bafile, a cap atthe end of the recess in which the outer end of the tube i slideablysupported and a spring between said cap and tube for urging the tube andbaffle endwise.

7. In shaft cooling, a shaft having a recess with a tapering wallportion, a bafile having a peripheral surface engaging said taperingwall portion,

and a spring for wedging said recess.

8. In shaft cooling, a shaft having a recess with a tapering wallportion, a bafiie having a peripheral surface engaging said taperingwall portion, a coolant tube having its inner end engaging said baflieand resilient means acting on said tube to wedge the baflie in therecess.

9. In shaft cooling, a shaft having a recess with a tapering wallportion, a baffle having a peripheral surface engaging said taperingwall portion, a coolant tube having its inner end engaging said baffle,a cap at the end of the recess in which the tube is axially slideable,and a spring between said baflle within the cap and tube for urging thetube and baflle endwise, said baffle and cap supporting the tuberadially, and said cap hving a passage through which coolant is admittedto the tube.

10. A shaft having a recess, a bafiie having a peripheral surfaceengaging the Wall of the recess, and resilient means for holding saidbattle in position.

11. A shaft having a recess, a baflle having a peripheral surfaceengaging the wall of the recess, a tube engaging said baflie, andresilient means acting on the tube to hold the baffle in position.

WALTER A. LEDWI'I'H.

